This adapter will couple firmly to the 079-00300 (FC-6446) type bleeder screw used in Cleveland and Matco brake systems so that you can properly bleed and charge the aircraft's brake lines and cylinder. The other end connects to any hose having a 1/4 NPT male thread. It will work with all bleeder tanks (such as our model 225 Economy Bleeder Tank) or other pressurized fluid systems. It locks firmly in place around the nipple and forms a high-pressure seal, so there is absolutely no chance of leaking fluid.